Reducing piece for glass instruments for laboratory technics



May 28, 1940. w. JUFFA 2,202,055

REDUCING PIECE FOR GLASS INSTRUMENTS FOR LABORATORY TECHNICS Filed July.15., 1937 "00 mag .W/LHELM JUFFA Patented May 28, 1940 UNITED STATESREDUCING PIECE FOR GLASS INSTRU- MENTS FOR LABORATORY TECHNICS WilhelmJnfl'a, Ihnenau, Germany Application July 15, 1937, Serial No. 153,730

In Germany March 16, 1937 3 Claims.

For filtering liquids it is known to use more or less-large bottlesprovided at one side with a suction pipe connection for producing apressure which is below atmospheric in the interior of thebottle, whilea specially-constructed filter head can befitted on the neck of thebottle.

This head consists of a large funnel with a molten-in so-calledsinter-plate. To obtain an air-tight closing, the filter funnel has astemoratory methods.

tube which extends into the bottle neck and on which a rubber ring canbe mounted.

Therefore, filter funnels of various size and also special tighteningmaterials, also of various size, are required.

The novelty of the present invention consists in that all these partsare omitted. The invention is based on the utilization of the teaching,given in applicant's U. S. A. Patent 2,052,713, to employ for liquidcontainers reducing glass pieces, ground air-tight on the inner side andon the outer side, and inserted one into the other for connecting thecontainer with tubes of diflerent diameter. By means of a loose filterplate which is simple to insert and to remove these reducing pieces canserve at the same time as a filter funnel.

The reducing pieces of known type open at the top and at the bottom arethus made useful for a new purpose, for which they are particularlysuitable, as, according to the U. S. A. patent cited above, they haveconical glass surfaces ground outside and inside. Thus, the filterfunnels,

hitherto required can be dispensed with as well as the packing material,since a number of reducing pieces according to the U. S. A. patent abovecited, when inserted one into the other possess the advantage ofcompensating for all the various sizes. With a single set of suchreducing pieces air-tight reduction from any external diameter to anyinternal diameter can be carried out.

At the same time, the application of the reducing pieces in the newcombination, and for the new purpose as filter funnel with automatictightening is particularly simple since only a simple sinter plate hasto be inserted loosely in the reducing piece from the top. If,afterwards the filter funnel is again to be used as a reducing piece, itis only necessary to remove the loose filter plate.

The invention, however, results in another surprising efiect: By meansof the reducing pieces a multiple filtration may be carried out. This isespecially advantageous for many chemical lab- As, according to theabove cited U. S. A. patent, several reducing pieces can be put togetherwithout appreciablylengthening the apparatus, it is possible, if thesinter plate has been loosely inserted into the inner reducing pieceright at the bottom, to insert sinter plates in the same way looselyinto the second or even into the third reducing piece, as the height ofthe single sinter plates is lower than the corresponding distancebetween the bottom edge of the first reducing piece and that of thesecond reducing piece and so forth.

Therefore, it is also an essential feature of'the invention that thesinter plate is loosely placed on the bottom edge of the correspondingreducing piece. Thus, according to the invention, it is possible tofilter several times in bottles of any size, with the aid of a fewsimple sinter plates which i have the normal size of the conicalreducing pieces,'because reducing pieces of various size are alreadyavailable.

The reducing piece, open at the top end and at the bottom, according tovthe above cited U. S. A. patent, can therefore also serve, according tothe present invention (1) As a filter funnel,

(2) As packing means,

(3) As a filter funnel and packing means of various sizes, fitting intoevery bottle neck,

(4) As a multifold filtering apparatus, and selectively:

(5) Either as a single, double or triple filtering apparatus, etc.

An embodiment of the invention is illustrated by way of example in theaccompanying drawing, in which Fig. 1 shows the bottle ready for use andFigs. 2 and 3 show the loose filter or sinter plate, suitable for normalreducing pieces.

I is the filter bottle, provided with a lateral connection 2 for theevacuation tube. A charging funnel 3 can be inserted into the neck ofthe bottleby means of one or a number of reducing pieces 4, 5.

The reducing piece or pieces has or have airtightly ground outer andinner surfaces so that by inserting a number of such reducing pieces itis possible to reduce the charging funnel to any desired cross section.

According to the invention, this normal reducing piece or these reducingpieces are used for a further purpose, i. e. as filtering container bythe loose insertion of a filter or sinter plate 6, which can be easilyremoved in the same manner. Therefore, when the filter plate isinserted, the reducing pieces engage each other air-tightly shutting offfiltering funnels and, after the easily 55 removable filter plates havebeen taken out, the reducing pieces are again suitable for reducingpurposes. As it is possible to only use one reducing piece, or, as shownin the drawing, several such pieces telescoped one into the other, thereducing pieces can serve as air-tight filtering funnels of any desiredsize.

If a filter plate 6 orrespectively is inserted, not only into the outerbut also into the irmer reducing piece, the reducing pieces can alsoserve as multi-filters, i. e. as double or triple filters. The chargingtunnel 3 remains nevertheless insertable. In this case the filter platesare placed on the bottom edge of the outer and of the inner reducingpiece. The liquid poured into the charging funnel 3 and drawn down bythe vacuum into the bottle 1, therefore, passes successively through thefilter plates 1 and 6.

The filter plates are made in known manner of glass, porcelain or thelike.

I claim:

1. In combination with a container and a tubular member; a device forinterconnecting said container and said tubular member, said devicecomprising at least one hollow conical reducing piece consisting ofglass, said reducing piece reducing the cross-section of said containerand having surfaces establishing an airtight connection between saidcontainer and said tubular member, and a loose filter plate removablymounted within said reducing piece to provide a filtering funnel.

2. In combination with a container and a tubular member; a device forinterconnecting said container and said tubular member, said devicecomprising a plurality of frusto-conical hollow reducing piecesconsisting of glass, each of said frustro-conical reducing pieces havingan exterior ground surface and an interior ground surface, said surfacesbeing concentric and extending over substantially the same portion ofthe length of the pieces, said reducing pieces telescoping with eachother, the exterior surface and the interior surface of each reducingpiece being adapted to establish an airtight connection with an adjacentsurface, the outer reducing piece engaging said container and the innerreducing piece engaging said tubular member, whereby the cross-sectionof said container is reduced by the reducing pieces, a loose filter.plate removably mounted within the outer reducing piece and a loosefilter plate removably mounted within the inner reducing piece, wherebythe telescoping reducing pieces serve as multi-filtering funnels.

3. A liquid container, a hollow member, a hollow conical reducing piececonsisting of glass and situated between said container and said memberto reduce the cross-section of said container, said reducing piecehaving a bottom edge; and a loose removable conical filter platesituated within said reducing piece and adjacent said bottom edge.

WILHELM JUFFA.

